It happened in broad day light -- an altercation between a large group of motorcyclists and a family inside a suv. Call it the violent video that has gone viral. Now crucial evidence for the nypd. The driver badly beaten and now recovering. But one biker could be paralyzed for life. Now with both sides hurling accusations and charges being filed, what really happened? Here is abc's linzie janice. Reporter: Imagine being out with a drive with your family on a sunday afternoon and suddenly you are surrounded by a swarm of motorcycles, roaring engines, angry bikers in every direction. That's what happened this weekend on a major highway in new york city before this scary confrontation spun violently out of control. And all caught on camera. Inside that black suv, 33-year-old banker alexy leone, his wife and young child. Watch as one biker appeared to stop short. When the suv hits him, the entire group of bikers comes to a grinding halt. When police say some of the motorcyclists got off their bikes and attacked the car. They take their helmets. Start to dent the car. Apparently his tires are slashed there, with a, with a knife. Reporter: He pulls off in terror, plowing through the crowd and severely injuring one biker as he escapes. And enraged the group takes off in hot pursuit. A three-mile high-speed chase in broad day light. After four terrifying minutes the motorcyclists swarm the suv once again when one rider ditches the bike and leone pulls it back and speeds off again. He is not safe. Trapped in traffic on the manhattan street with nowhere to hide. The bikers attack. One of them smashing the driver side window with his helmet another using his fist. That's when the video cuts out. Police say the nightmare continues. He is beaten in front of his family and left on the road in a pool of his own blood. He was later treated and released at a nearby hospital. But of the biker that he mowed down as he tried to get away wasn't so lucky. Tonight that man, 32-year-old, is fighting for his life. All his ribs are broken. His spine is broken in two places. He is never going to walk. Never going to walk again. The wife of the paralyzed man defend her husband and the riders. Everyone got worried. Everyone stops. My husband stops. Doesn't throw his bike. Parks it. And walks on over to try to help the guy. His brother agrees. Watching too much sons of anarchy. He assumed he was going to be hurt. That was not the case at all. Reporter: The police are not so sure. Well it depend on what the circumstances are, depends on whether or not, your vehicle is being attacked, whether or not you think you are being attacked, whether or not your wife and child are in the car, you have to look at the totality of the circumstances. That's what we are doing. Reporter: Who were the bikers, what are they doing in new york city? Gatherings like these, a kind of biker flash mob happen all over the country. Basically groups of riders organize stunts and temporarily take over highways just for laughs. This past january, in california, a group of bikers blocked a four-lane freeway, just so that one of the riders could propose to his girlfriend. He celebrates by spinning his wheels to create a cloud of pink smoke. The group of thrill seekers that took to manhattan last weekend call themselves the hollywood stunts. Last year they invaded times square. Posting this video online. But this year, police were determined not to let that happen. Quite frankly, it wasn't on anybody's radar screen last year. We were aware of it this year. And did a fair amount of enforcement. Reporter: They arrested 15 riders and confiscated 55 bikes over the weekend. Abc news contacted hollywood stunts. They told us, under no circumstances do we condone any type of violence, hate or any riding that can harm pedestrians or riders. But we found helmet-cam video posted by a member of the group from two years ago showing similar reckless behavior. The bikers weaving in and out of traffic and ending up attacking this car. We want to belter understand the motivation behind these rides and the stunts that so often go along with them. I have been insome l soimilar situations. Let's check it out. Reporter: We took a drive with a professional stunt rider, nick, who learned his trade out on the open road. Here we are, nick where that initial confrontation happened, that initial accident between the suv and one of the bikers. Nick used to participate in organized stunt rides like the one last sunday. I can tell you right away before you go any further this stretch of road is straight and smooth. So if, if it were me, this would be a great section to do a trick. Reporter: All of the bikers stopped and surrounded the suv, did they all need to stop? Why did they all stop? That is the question. Reporter: Do you know why? Is it code? These guys, probably they want separation between the group of bikes and cars behind them to do their tricks. So if, if I'm just hypothetically. If there was a car too close, and you are trying to do the tricks you would want them to back away. Reporter: Disrupting traffic to do tricks is of course entirely illegal. Nick says that doesn't stop many stunt riders. When you got more than one book on the road. You got one guy might pop it up. Some guy might try to do a wheely. Some other guy will say watch this. When you get more people in the group, they kind of egg each other on. Nick has since reformed his street riding ways and now only performs his stunts on closed courses. He says, other riders should do the same. If they want to exceed the speed limit want to do any stunts itch you wf you will, a time and place. Not on the street. Reporter: As for this weekend's street ride gone terribly wrong. Police have made some progress, arresting this biker and charging him with reckless endangerment for causing the accident that triggered the horrific chain of events. They're also questioning another suspect, who police believe may be the man seen here. Pounding the suv with his fists. They're still searching for this biker. More evidence of this hobby's serious consequences, not just for the stunt doubles themselves, but for those us that have to share the road with them. For "nightline," linzie janice in new york.

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